I've worked with epoxy putty nearly all my life as my main sculpting material on custom figures. I finally bought a dremel last year which greatly increased my productivity but it also increased the amount of epoxy putty I needed to use (I currently have 17 empty Loctite bottles sitting on my desk). And over the years it hadn't even occured to me that it may have been affecting my health. And I think this would be the only place where I could get a good answer for this question. So can breathing in the fumes when mixing the putty or the dust that comes from sanding the hardened putty harm you in any serious ways?

when I used too use apoxy Someone in my family had a huge allergic reaction to it, so I had to stop using it. I did sand it quite frequently and I don't believe the dust did to much other than the occasional sneeze or cough, but that is Apoxy it could be completely different than Epoxy. Hope this helps.